This invention relates to apparatus for effecting the rotation of a device, and more specifically, to a rotator operative for accomplishing the rotation of a reactor coolant pump and flywheel such that an examination by ultrasonic and/or eddy current means may be had of the flywheel.
There are known to exist many instances wherein it is desirable and/or necessary to effect an examination, and in particular a surface examination, of an operating component. Notwithstanding the number of such instances and the differences that exist therebetween, in general one finds that the reason for conducting such an examination is associated in some manner with the need to determine the relative operating condition of the component in question. That is, commonly there exists a need to ensure the operability of the component preparatory to its being placed in service and/or the need periodically to certify that the component is still in good working order. To this end, it is not uncommon to find that standards have been promulgated in this regard for various kinds of operating components. Namely, these standards, which have been promulgated, serve to establish the nature and/or extent of the defects, which will be deemed to render a particular type of operating component unserviceable.
By way of exemplification and not limitation, reference is had here to rotary members, as being representative, generally, of one such form of component. Further, one specific type of rotary member to which reference may be made in this connection is that of flywheels, and in particular flywheels of the sort, which often are found cooperatively associated with the coolant circulation pump motors that are employed in nuclear steam supply systems. The function which flywheels perform in this type of a nuclear-related application is that of assisting in the accomplishment of coastdown of the coolant circulation pump motors. As such, it is, therefore, important that when the flywheels are needed that they be capable of functioning in their intended manner. To this end, obviously one way of ensuring that the flywheels are in good working order is to periodically conduct an examination of the flywheels for defects. Moreover, rather than depending on compliance with some voluntary schedule of examination of such components, it is known that in a number of instances governmental authorities have promulgated regulations that mandate the performance of such periodic examination with regard to particular components for purposes of effecting a detection of defects therein that could impair the operativeness of the component. This is particularly true in the case of many of the operating components of a nuclear steam supply system.
With specific regard to flywheels of the sort referred to above, i.e., the large flywheels needed for coastdown in nuclear reactor coolant circulation pump motors, existing governmental regulations require that they undergo surface examinations during preservice and at ten year intervals during the life of the nuclear plant in which they are installed. Note is taken here of the fact that in requiring that surface examinations be performed on such flywheels, governmental regulations have not only specified the frequency of such examinations and the nature of the defects which the surface examination was intended to detect, but have also dictated the manner in which the examination is to be performed. Namely, such governmental regulations have heretofore required that the surface examination be conducted in accordance with the procedures that are found set forth in the applicable industrial codes, which have been promulgated governing the performance of surface examinations of metal components.
By way of exemplification in this regard, one method that has been found suitable for use for purposes of performing a surface examination of a coated component such as the flywheel associated with the coolant circulation pump motor employed in a nuclear power generation system forms the subject matter of co-pending U.S. Patent Application Ser. No. 266,397, now U.S. Pat. No. 4,418,315, which was filed in the name of Lawrence J. Edwards and John P. Lareau, and which is assigned to the same assignee as the present application. The method which forms the subject matter of the aforereferenced U.S. patent has been deemed to be acceptable under the applicable industrial codes as a technique which is recognized for use for the purpose of surface examinations of metal components. As described in the aforementioned U.S. patent, the subject method includes the steps of providing a calibration block embodying characteristics similar to the component that is to undergo the surface examination and having a plurality of crack-like notches formed in a surface thereof, providing a layer-like film of nonmetallic material embodying characteristics similar to the coating borne by the component that is to undergo the surface examination, positioning the layer-like film of nonmetallic material in superimposed relation on the calibration block so as to cover the plurality of crack-like notches formed in the calibration block, establishing with eddy current means calibration readings from the calibration block having the layer-like film of nonmetallic material positioned in superimposed relation thereto, performing a surface examination of the coated metal component with the eddy current means by moving the eddy current means over the surface of the coated metal component in a traversing pattern corresponding to the pattern defined by the plurality of scribe lines provided on the layer-like film of nonmetallic material, and comparing the readings obtained from the surface examination of the coated metal component with the calibration readings obtained from the calibration block to establish the presence of any cracks of at least a minimal dimension in the surface of the coated metal component. In the case of many known methods for performing a surface examination of a component, including the method described in this paragraph, there is a need in order to satisfactorily accomplish the examination therewith that relative motion be made to take place between the component, which is the subject of the examination, and the means with which the examination is being conducted. More specifically, in accord with some of the known methods for performing a surface examination of a component, the means by which the examination is conducted is required to be made to move relative to the component undergoing examination. While yet on the other hand, other methods for performing a surface examination of a component require that the component being examined be moved relative to the means, which is being utilized in the conduct of the examination.
As concerns those methods of examining components wherein there is a requirement that the component undergo movement in order to accomplish the examination thereof, the manner in which this movement of the component is effectuated is of prime importance to the successful performance of the examination. In this regard, it is of prime importance that consideration be given to factors, which by way of exemplification and not limitation, include items such as the following: the weight and size of the component, the ease of accessibility to the component, the nature of the movement be it rotational or translational which the component is required to undergo, the consistency of the movement required in terms of the deviation permitted from a given mean, the repeatability required as between subsequent tests, etc.
Continuing, with regard, for instance, to the matter of weight and size, the component which is to undergo the subject examination may be so heavy and/or have such large dimensions that it would be virtually impossible to manually impart thereto the movement desired. On the other hand, insofar as accessibility is concerned, the location of the component to be examined may be such as to preclude the use of some form of mechanical means to impart movement thereto. In terms of whether the component being examined is required to undergo rotational or translational motion, normally it would be possible to impart either of those types of motion to the component either manually or through some suitable form of mechanical means. In those instances wherein consistency and repeatability are required, the use of some form of mechanical means to impart movement to the component in question would most often be necessitated.
Attention will now be focused on a specific application wherein a need exists to impart movement to a component for purposes of performing an examination thereof. More specifically, reference is had here to coolant pumps of the type that one finds being employed in a nuclear steam supply system. With respect to such pumps, a requirement exists that they undergo examination. This examination commonly takes the form of an ultrasonic and eddy current examination of the flywheel that is cooperatively associated with the pumo motor. Moreover, in order to accomplish this examination the flywheel and pump motor must be rotated. Heretofore, for purposes of accomplishing this rotation of the flywheel and pump motor the practice has been to effect this rotation manually. That is, although the force that is required to be applied in order to accomplish the desired rotation of the flywheel and pump motor has normally been found to be of greater magnitude than a person is capable of exerting without assistance, by making use of the mechanical advantage that can be derived from the employment of a mechanical device such as a lever, it has been possible to manually accomplish the desired rotation of the flywheel and pump motor. However, though it has been possible in this manner to effect the rotation of the flywheel and pump motor, a less cumbersome and more efficient method has been sought for accomplishing this purpose. Accordingly, a need has thus been evidenced in the prior art for a new and improved apparatus suitable for use for purposes of effecting the rotation of a component such as a reactor coolant pump motor and flywheel, and one which is particularly useful when the rotation desired is necessitated by the need to subject the component to an examination, as for example, of an ultrasonic and eddy current nature.
It is, therefore, an object of the present invention to provide a new and improved apparatus operative for purposes of effecting relative motion between a component and another device.
It is another object of the present invention to provide such an apparatus which for purposes of effecting relative motion between a component and another device is operative to impart rotation to the component.
It is still another object of the present invention to provide such an apparatus which is particularly suited for use for purposes of imparting rotation to a component wherein the component is required to be rotated in order to conduct an examination thereof.
A further object of the present invention is to provide such an apparatus which is particularly suited for use for purposes of effecting the rotation of a reactor coolant pump motor and flywheel in order that an examination may be conducted thereof.
A still further object of the present invention is to provide such an apparatus operative for purposes of imparting rotation to a reactor coolant pump motor and flywheel wherein the apparatus is characterized in that a constant speed of rotation is capable of being imparted therewith.
Yet another object of the present invention is to provide such an apparatus operative for purposes of imparting rotation to a reactor coolant pump motor and flywheel wherein the apparatus is characterized in that it is relatively easy to install, relatively simple to operate, yet is relatively inexpensive to provide.